The development of photoreceptor-specific proteins, including Red/Green (R/G) and Blue (B) opsin for cones and rhodopsin for rods, and of other proteins involved in the visual cycle, including transducin and the structural protein peripherin, have been determined for the macaque retina. Sequential waves of opsin expression move across the retina, beginning in the fovea at Fd66-70, with rhodopsin expressed first, B opsin slightly later (Fd70), and R/G opsin expressed last with a significant delay. Several tests of expression patterns suggest that each opsin is expressed independently of the others and does not influence neighboring photoreceptor opsin phenotypic choice. Peripherin is expressed at the same time as opsin in each cell type. The two proteins overlap spatially and temporally, suggesting that both are required to construct the photosensitive region of the cell, the membrane-rich outer segment (OS). On the other hand, transducin appears well after photoreceptors have formed an OS, indicating that it is added to the OS membrane close to the time that phototransduction begins.